[PATCH AUTOSEL 6.11 179/244] drm/amd/display: Initialize denominators' default to 1

Sasha Levin
2024-09-25T11:48:29Z

From: Alex Hung <alex.hung@amd.com>

[ Upstream commit b995c0a6de6c74656a0c39cd57a0626351b13e3c ]

[WHAT & HOW]
Variables used as denominators and maybe not assigned to other values,
should not be 0. Change their default to 1 so they are never 0.

This fixes 10 DIVIDE_BY_ZERO issues reported by Coverity.

Reviewed-by: Harry Wentland <harry.wentland@amd.com>
Signed-off-by: Jerry Zuo <jerry.zuo@amd.com>
Signed-off-by: Alex Hung <alex.hung@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
.../gpu/drm/amd/display/dc/dml/dcn20/display_rq_dlg_calc_20.c | 2 +-
drivers/gpu/drm/amd/display/dc/dml/dml1_display_rq_dlg_calc.c | 2 +-
.../display/dc/dml2/dml21/src/dml2_core/dml2_core_shared.c | 4 ++--
3 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/amd/display/dc/dml/dcn20/display_rq_dlg_calc_20.c b/drivers/gpu/drm/amd/display/dc/dml/dcn20/display_rq_dlg_calc_20.c
index 7c56ad0f88122..e7019c95ba79e 100644
--- a/drivers/gpu/drm/amd/display/dc/dml/dcn20/display_rq_dlg_calc_20.c
+++ b/drivers/gpu/drm/amd/display/dc/dml/dcn20/display_rq_dlg_calc_20.c
@@ -78,7 +78,7 @@ static void calculate_ttu_cursor(struct display_mode_lib *mode_lib,

static unsigned int get_bytes_per_element(enum source_format_class source_format, bool is_chroma)
{
- unsigned int ret_val = 0;
+ unsigned int ret_val = 1;

if (source_format == dm_444_16) {
if (!is_chroma)
diff --git a/drivers/gpu/drm/amd/display/dc/dml/dml1_display_rq_dlg_calc.c b/drivers/gpu/drm/amd/display/dc/dml/dml1_display_rq_dlg_calc.c
index dae13f202220e..d8bfc85e5dcd0 100644
--- a/drivers/gpu/drm/amd/display/dc/dml/dml1_display_rq_dlg_calc.c
+++ b/drivers/gpu/drm/amd/display/dc/dml/dml1_display_rq_dlg_calc.c
@@ -39,7 +39,7 @@

static unsigned int get_bytes_per_element(enum source_format_class source_format, bool is_chroma)
{
- unsigned int ret_val = 0;
+ unsigned int ret_val = 1;

if (source_format == dm_444_16) {
if (!is_chroma)
diff --git a/drivers/gpu/drm/amd/display/dc/dml2/dml21/src/dml2_core/dml2_core_shared.c b/drivers/gpu/drm/amd/display/dc/dml2/dml21/src/dml2_core/dml2_core_shared.c
index 81f0a6f19f87b..679b200319034 100644
--- a/drivers/gpu/drm/amd/display/dc/dml2/dml21/src/dml2_core/dml2_core_shared.c
+++ b/drivers/gpu/drm/amd/display/dc/dml2/dml21/src/dml2_core/dml2_core_shared.c
@@ -9386,8 +9386,8 @@ static void CalculateVMGroupAndRequestTimes(
double TimePerVMRequestVBlank[],
double TimePerVMRequestFlip[])
{
- unsigned int num_group_per_lower_vm_stage = 0;
- unsigned int num_req_per_lower_vm_stage = 0;
+ unsigned int num_group_per_lower_vm_stage = 1;
+ unsigned int num_req_per_lower_vm_stage = 1;

#ifdef __DML_VBA_DEBUG__
dml2_printf("DML::%s: NumberOfActiveSurfaces = %u\n", __func__, NumberOfActiveSurfaces);
--
2.43.0